The present invention is concerned with computer systems, and is more particularly concerned with disk drives used for mass storage of data in computer systems.
Disk drives are well known components of computer systems. Advances in disk drive technology have led to substantial increases in storage capacity, increased disk rotation speeds, and lower head flying heights. With these advances, there has been an increased need to detect conditions that may indicate that a head crash is imminent. Detection of such so-called xe2x80x9cpre-crashedxe2x80x9d conditions is referred to as xe2x80x9cpredictive failure analysisxe2x80x9d. Conventional predictive failure analysis involves measuring a number of operating parameters of the disk drive, including head flying height, hard error rates, soft error rates, vibration, and disk run out checks, and comparing such parameters with predetermined thresholds. According to known practices, predictive failure analysis is performed at regular time intervals, such as every four hours. It is also known, when a predictive failure analysis indicates a failure, to immediately perform the predictive failure analysis once again to confirm or reject the indication of failure. When a failure is indicated or confirmed by a predictive failure analysis, a warning may be issued to a host computer so that suitable preventive measures may be taken, such as transferring data from the disk drive and/or replacing the disk drive.
With the continuing advances in disk drive technology, the present inventor has recognized that it is desirable to provide for more stringent predictive failure analysis, while at the same time not unduly increasing the burden that predictive failure analysis imposes on disk drive operation.
According to a first aspect of the invention, a method of operating a disk drive includes detecting a trigger event during non-idle operation of the disk drive. Further according to this aspect of the invention, the method includes responding to the detected trigger event by performing a predictive failure analysis with respect to the disk drive. The predictive failure analysis may include, for example, one or more of flying height measurement, hard error rate measurement, soft error rate measurement, measurement of vibration, a disk run out check, a recording head measurement, and a servo system measurement.
According to a second aspect of the invention, a method of operating a disk drive includes performing a predictive failure analysis with respect to the disk drive at a regular time interval, detecting a trigger event during non-idle operation of the disk drive, and responding to the detected trigger event by reducing the regular time interval at which the predictive failure analysis is performed.
According to a third aspect of the invention, a method of operating a disk drive includes performing a predictive failure analysis with respect to the disk drive at a regular time interval, where the predictive failure analysis includes measuring an operating parameter of the disk drive and comparing the measured operating parameter against a first threshold and a second threshold. The method according to this aspect of the invention further includes reducing the regular time interval at which the predictive failure analysis is performed if the measured operating parameter exceeds the first threshold, and indicating a failure if the measured operating parameter exceeds the second threshold. The method may further include increasing the regular time interval at which the predictive failure analysis is performed if the measured operating parameter falls below a third threshold. The third threshold may be the same or different than the first threshold.
According to a fourth aspect of the invention, a method of operating a disk drive includes detecting a trigger event with respect to a particular data sector of the disk drive during non-idle operation of the disk drive, and in response to the detected trigger event, performing a flying height measurement with respect to the particular data sector. The method according to this aspect of the invention may further include relocating data from a cylinder that includes the particular data sector to another portion of the disk drive based on a result of the flying height measurement.
According to a fifth aspect of the invention, a method of operating a disk drive includes detecting a defect in a first cylinder of the disk drive, and in response to the detected defect, relocating to another portion of the disk drive data stored in a plurality of adjoining cylinders including the first cylinder.
According to further aspects of the invention, the inventive methods set forth above may be performed in a disk drive that includes at least one disk-shaped data storage medium, at least one head for reading data from and writing data to the storage medium, and a controller for controlling movement of the at least one head. Numerous other aspects are provided, as are computer program products. Each inventive computer program product may be carried by a medium readable by a computer (e.g., a carrier wave signal, a floppy disk, a hard drive, a random access memory, etc.).
Aspects of the invention may improve prediction of head crashes, without unduly increasing the overhead associated with predictive failure analysis. Other aspects of the invention may improve performance of a disk drive by moving data from portions of the disk medium which are defective and setting aside the defective portions.
Other objects, features and advantages of the present invention will become more fully apparent from the following detailed description of exemplary embodiments, the appended claims and the accompanying drawings.